Robert Ian Mackenzie was 3 years old when he decided he wanted to be an actor. But to say the British thespian took a circuitous path to the stage seems like an understatement.

Mackenzie, who turns 67 this month, tried his hand at more than 20 different occupations before venturing into the world that had beckoned the moment his parents took him to see his first Christmas pantomime as a boy.

"I wanted to act. I didn't have the courage of my conviction," says Mackenzie, who takes the stage as Mr. Bennet in the Bristol Riverside Theatre's production of "Pride & Prejudice," adapted by Jon Jory and opening Thursday. "I didn't feel I was equipped to do it."

Between the ages of 19 and 31, he held down an impossibly varied number of jobs, from London policeman and assistant in a smoked salmon business to water ski instructor, venetian blind installer and a Christmas deliveryman with additional stints in the insurance and travel industries. He toiled in England and Greece and Switzerland, finding fleeting fulfillment and plenty of frustration as he tried to forge a sustainable career. And then one day, while on the Greek island of Rhodes, he met Jack Watson, one of England's most popular actors.

As Mackenzie accompanied Watson out to sea on a rowboat, he listened to him talk of his craft  and realized he'd delayed the inevitable long enough. He returned to London, quit his job as general manager of an upholstery company and began plotting a path to the stage.

It's one that's garnered him roles in opera, theater, film and television. He's appeared on stages in New York, in several productions with Stageworks/Hudson and Ensemble for the Romantic Century, among others, and in London's West End. His many regional credits include "Forget Hoerostratus" and "Dr. Jekyll and Mr. Hyde" at the BRT, and in addition to featured roles in "Guiding Light" and "All My Children," he's had parts in films like "The Long Kiss Goodnight," "The Thomas Crown Affair" and "The Good Shepherd."

But while he's obviously exhilarated to be doing what he always dreamed of, Mackenzie has never fully overcome the shyness that impeded an earlier start to his career.

"A lot of actors, we're semi-terrified when we walk out onstage," he says. "Then suddenly, there's your cue. You walk out there and you're in a different world. It's magical."

As a child, sitting in the audience was magical, too. Mackenzie, who grew up between Durham and Newcastle, just north of London, still remembers how fascinated he was by the trap doors in the Gilbert & Sullivan opera "The Gondoliers," and to this day, the curtain remains a bit of theatrical enchantment he wishes more houses would employ.

"That moment when the red velvet curtain with the gold all over it just rises up and you see that different world  it used to transport me," says the actor, who is now based in Manhattan.

Interestingly enough, he did take to acting while in junior school, starting at age 8. He was in every production there, and at 12 played both Ebenezer Scrooge in "A Christmas Carol"  a role he's since inhabited six times, along with two turns as Jacob Marley's Ghost  and the Bishop in "The Bishop's Candlesticks."

Yet when his parents would arrange for him to take acting classes or send him off to kids' theater camps, he always balked, disappearing for hours until it was too late to catch the train. But he got an unlikely education as a member of the Metropolitan Police Service.

"Being a policeman gave me great insight into human nature and people. That was the start of my drama training," says Mackenzie, recalling all the mock courtroom setups and other staged scenarios he'd have to react to as a would-be-officer. "You got to see prostitutes, drug dealers, the aristocracy, who talked down to you ... there was so much to observe."

When he left the force after an injury, he uttered what would become a familiar refrain: "I've got to be an actor." But it would take several more years for him to make the leap.

When he did, he would find a remarkable ally. After his encounter with Watson, Mackenzie got a job working for Video Arts, a London company that specializes in humorous corporate training videos. At the time, John Cleese was one of its directors. When he wasn't helping out with props or other tasks on set  he did a 25-foot drop from a tree once, standing in for a stunt man  he served as Cleese's chauffeur.

It was Cleese, who, after learning of Mackenzie's desire to be an actor, dashed off several letters to some of the region's finest repertory theaters, suggesting he might make a good addition to their stage management team. Mackenzie didn't know Cleese had done this until he received a call from the production manager at the Royal Lyceum Theatre in Edinburgh, Scotland, who raved about the letter he'd received before offering him a job.

For three months, Mackenzie worked behind-the-scenes there until he was hired away by the Bristol Old Vic, where he landed his first walk-on role in David Edgar's "Destiny"  with only three hours to prepare.

"I'll never forget it. It was a disaster," says Mackenzie, who had his written lines in front of him since his back was to the audience but began to sweat so profusely upon forgetting them, he couldn't read the words. "There was this long silence ... and then I remembered, and I was off. But when I left the stage, I thought, 'Why would anybody ever want to do this?' "

He was nonetheless hooked and after seven months in Bristol, returned to London with his equity card. As he continued to expand his résumé, he would get one more boost from Cleese, who offered him a role as a police officer in "A Fish Called Wanda."

Though mainstream success has been elusive, he's kept a steady pace.

"I've been a working actor for over 35 years. I rarely have a break," says Mackenzie. "That gives me a good buzz."